The present invention relates to an inkjet printing device used for printing images such as photographs or designs on a substrate.
For printing photographs or designs on a substrate such as fabric and a sheet, a screen printing technique is frequently used. In the screen printing, on the fabric, for example, a stencil is placed, and then ink is pressurized to be transferred through the stencil from the outside of the stencil. Thus, an image is printed on the fabric.
Since the screen printing requires that an ink image is formed on the stencil before printing operation, making screens is troublesome. Further, production cost is increased when the image to be printed is an intricately colored image (e.g., a landscape picture or a portrait) although the screen printing is convenient for a monotonal color pattern image or a monochrome pattern image.
To avoid the above mentioned problem of the screen printing, recently the inkjet printing device for forming an image on the fabric is widely used. In general, the inkjet printing device includes an inkjet head having a plurality of ejection channels. In the inkjet head, actuators such as heater elements and piezoelectric devices are selectively driven to eject ink from desired ones of a plurality of nozzles provided at tip portions of the plurality of ejection channels.
In many cases, the substrate on which the image is formed by the inkjet printing device is a standard sheet. In the inkjet printing device that uses the standard sheet as the substrate, the image is formed on the sheet while the sheet is carried along a sheet carrying path.
With regard to the inkjet printing device which uses the fabric (e.g., a T-shirt) as the substrate, unlike a sheet it is difficult to set a T-shirt at a proper position and keep its shape unchanged while the T-shirt is carried along a carrying path in the inkjet printing device. Therefore, in general a platen is used in the inkjet printing device to set a T-shirt and keep its shape unchanged while the T-shirt is carried in the inkjet printing device. In the inkjet printing device, the platen holding the T-shirt is moved relative to the inkjet head while the ink is ejected from the inkjet head.
When the printing operation is performed, it is required to precisely position the T-shirt with respect to the inkjet head so that the ink is ejected at required positions on the T-shirt.
In U.S. Pat. No. 6,095,628, the inkjet printing device for the fabric is disclosed. In this inkjet printing device, an inkjet head is supported on a housing such that the inkjet head can reciprocate in a lateral direction, and a platen is supported on two rails such that the platen can move along the two rails in a longitudinal direction of the housing. With this structure, the platen holding the T-shirt is precisely positioned with respect to the inkjet head.
By loading the T-shirt onto the platen, the position of the T-shirt with respect to the inkjet head is precisely fixed. Then, the platen is moved to a position beneath the inkjet head with a holding surface of the platen being kept horizontally. Next, the inkjet head ejects the ink in the downward direction to form an image on the T-shirt.
Before the T-shirt is loaded onto the platen, the platen is firstly moved to a front end position. Then, a worker loads the T-shirt onto the platen by pushing the bottom of the T-shirt toward the rear side of the housing of the inkjet printing device from the front side.
The T-shirt is loaded onto the platen so that a working surface (on which the image is printed) of the T-shirt faces the upward direction. Then, the direction of the working surface is adjusted and the position of the platen with respect to the inkjet head is adjusted.